An implementation of the Ark second-layer payment protocol for Bitcoin.
This repository comprises an ASP server, arkd, a client wallet, noah, and
a library that contains all the primitives used for these implementations.
You can play around with the tools as follows:
First you have to setup a regtest bitcoind node, there is a script provided for that. If you want to run your own node, keep in mind that for now, we need it to have the txindex enabled.
$ ./run_bitcoind.sh
You can interact with the node using bitcoin-cli as follows:
$ bitcoin-cli -regtest -rpcuser=user -rpcpassword=pass getnetworkinfo
Then, you can run an arkd server:
$ cargo run --bin arkd
This will start the server and it will work immediatelly. The configuration
currently is hard-coded in the arkd/src/main.rs file, and can only be changed
there. For arkd to work properly, you should fund it with some liquidity, this
can be done by sending some money to the address that is printed out when arkd
is started. You can send money there as follows:
$ bitcoin-cli -regtest -rpcuser=user -rpcpassword=pass generatetoaddress 1 <asp-addr>
# Then give it 100 confirmations because it's a coinbase output.
$ bitcoin-cli -regtest -rpcuser=user -rpcpassword=pass generatetoaddress 100 mtDDKi5mDjZqGzmbnfUnVQ8ZhCPMPVsApj
Next, you can start some clients. To create a client, use the following command:
$ cargo run --bin noah -- --datadir ./test/noah1 create
$ cargo run --bin noah -- --datadir ./test/noah2 create
These will create individual wallets and print an on-chain address you can use to fund them the same way as you did for the ASP above. Note that clients can receive off-chain Ark transactions without having any on-chain balance, but a little bit of on-chain money is needed to perform unilateral exits.
To use the onchain wallets, there are a few commands available:
$ NOAH2_ADDR=$(cargo run --bin noah -- --datadir ./test/noah2 get-address)
$ cargo run --bin noah -- --datadir ./test/noah1 send-onchain $NOAH2_ADDR "0.1 btc"
$ cargo run --bin noah -- --datadir ./test/noah2 balance
Once we have money, we can onboard into the Ark, afterwards the balance will also show an off-chain element.
$ cargo run --bin noah -- --datadir ./test/noah1 onboard "1 btc"
$ cargo run --bin noah -- --datadir ./test/noah1 balance
Remember that all txs will just be in the mempool if you don't generate blocks once a while...
$ bitcoin-cli -regtest -rpcuser=user -rpcpassword=pass generatetoaddress 1 mtDDKi5mDjZqGzmbnfUnVQ8ZhCPMPVsApj
Then, let's send some money off-chain to a third wallet:
$ cargo run --bin noah -- --datadir ./test/noah3 create
$ cargo run --bin noah -- --datadir ./test/noah3 balance
# Should be empty..
$ NOAH3_PK=$(cargo run --bin noah -- --datadir ./test/noah3 get-vtxo-pubkey)
# For now every client has just a single pubkey.
$ echo "${NOAH3_PK}"
$ cargo run --bin noah -- --datadir ./test/noah1 send ${NOAH3_PK} "0.1 btc"
$ cargo run --bin noah -- --datadir ./test/noah3 balance
You will notice that there is a slight delay when sending, this is because the client needs to wait for the start of the next round and currently no out-of-round payments are supported. The round interval can be changed in the arkd configuration.